Probing a leptophobic top-colour model with cross section measurements and precise signal and background predictions: A case study

The sensitivity of particle-level fiducial cross section measurements from ATLAS, CMS and LHCb to a leptophobic top-colour model is studied. The model has previously been the subject of resonance searches. Here we compare it directly to state-of-the-art predictions for Standard Model top quark production and also take into account next-to-leading order predictions for the new physics signal. We make use of the Contur framework to evaluate the sensitivity of the current measurements, first under the default Contur assumption that the measurement and the SM exactly coincide, and then using the full SM theory calculation for t t over bar at next-to-leading and next-to-next-to-leading order as the background model. We derive exclusion limits, discuss the differences between these approaches, and compare to the limits from resonance searches by ATLAS and CMS.

Automated summary

This study investigates the sensitivity of particle-level fiducial cross section measurements from ATLAS, CMS, and LHCb to a leptophobic top-color model. The model, which has been previously the focus of resonance searches, is directly compared to state-of-the-art predictions for Standard Model top quark production. Next-to-leading order predictions for the new physics signal are also taken into account. Contur framework is used to evaluate the sensitivity of the current measurements, first assuming the measurement and the SM exactly coincide and then using the full SM theory calculation for t t over bar at next-to-leading and next-to-next-to-leading order as the background model. Exclusion limits are derived, the differences between these approaches are discussed, and the limits from resonance searches by ATLAS and CMS are compared.